Pipe forming machine



June 5, 1956 A. F. BUTCHER 2,748,442

PIPE FORMING MACHINE Filed March 15, 1954 v 2 Sheets-Sheet 1 INVENTOR A. I. Baicber 4 TTYS June 5, 1956 A. F. BUTCHER 2,748,442

PIPE FORMING MACHINE Filed March 15, 1954 2 Sheets-Sheet 2 Q I Q Q Q Q INVENTOR i fiZFBuZcber I BY H TTYS United States Patent PIPE FORMING MACHINE Albert Floyd Butcher, Modesto, Calif.

Application March 15, 1954, Serial No. 416,134

3 Claims. (Cl. 25-32) This invention relates to a machine to form concrete pipe and lay the same in a preformed ditch or trench.

A major object of my invention is to provide a ma chine for the purpose by means of which pipe will be formed and laid in the trench in such a manner that the machine will automatically advance, or back away from the pipe as it is formed. 'To this end, the means to form and extrude the pipe from the machine also causes the machine to so advance, so that said machine is self-propelled Without the need of a tractor or the like being attached to the machine to move the same along the trench.

Another object of the invention is to arrange the machine so that the initial concrete mix as fed to the machine is properly compressed or compacted before it is extruded in the pipe form, and there are no breaks in the continuity of the concrete, or in the degree of compaction thereof, from said initial mix to the finally laid pipe; thus avoiding cracking, and insuring a pipe of the same density throughout its extent. In other words, a continuous or monolithic pipe, with no scams or joints, pot holes or soft spots, or the like, is formed.

Another object of the invention is to form the outer pipe-size determining member of the machine so that the cross-sectional form of the pipe, as extruded into the trench, will be such as to tend to prevent possible collapse ofthe upper unsupported portion of the still green pipe.

Still another object of the invention is to provide a pipe forming machine which is designed for ease and economy of manufacture.

It is also an object of the invention to provide a practical, reliable, and durable pipe forming machine, and one which will be exceedingly eflective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as willfully appear by a perusal of the following specification and claims.

In the drawings:

Fig. 1 is a side elevation of the improved pipe forming machine, shown as with the concrete advancing piston retracted.

" 'Fig. 2 is a fragmentary enlarged sectional elevation of the machine, together with the formed pipe; the concrete-advanced piston being fully advanced.

Fig. 3 is a cross section on line 3-3 of Fig. 1.

Fig. 4 is a discharge end view of the machine.

Fig. 5 is a cross section of the pipe as formed in the trench.

Referring now more particularly to the drawings and to the characters of reference marked thereon, the machine comprises an elongated barrel 1; the discharge end portion 2 of which is of a diameter to fit the halfround bottom contour of the pre-dug trench 3 in which the pipe is to be laid. The intake or forward end portion 4 of the barrel forms a cylinder of somewhat smaller diameter than the trench, and is connected to portion 2 by a relatively short sloping wall 5. The cylinder 4 is Patented .lune 5, 1956 'ice however supported from the floor of the trench by a suitably shaped shoe 6. I

Mounted in the barrel is a core' 7 of circular contour throughout its extent, and of hollow construction for the sake of lightness. This core comprises a relatively small-diameter member 8 substantially the length of the cylinder 4 and removably secured, as by a threaded connection 9, in the forward end head 10 of the cylinder; the member 8 being concentric with the cylinder.

At its opposite or outer end the core is formed with a short cylindrical portion 11 concentric with the barrel portion 2, and whose diameter relative thereto determines the thickness of the pipe 12 to be formed, and the outer diameter of which pipe is that of the interior of barrel portion 2. The sleeve portion 11 projects beyond the end of barrel portion 2 a short distance; said portion 2 being cut back somewhat from the bottom up, as shown at 13. The core portion 11 is connected to the rear end of the member 8 by a portion 14 of gradually decreasing diameter, followed by a portion 15 of sharper taper, as shown in Fig. 2.

The member 8 is of relatively substantial and rigid construction, as is the connection 9, so that the core as a whole will remain supported in concentric relation to the barrel without the need of any bracing fins or the like being needed between the barrel and core, and which would interfere with the fiow of concrete therebetween.

A hopper 16 projects upwardly from the cylinder 4 adjacent its forward end, so that concrete may be fed into the cylinder from a supply carried on a mixer (not shown) supported from the ground to one side of the trench 3. r

Slidable in the cylinder is a piston 17 of ring-like form, engaging both the inner wall of the cylinder 4 and the outer wall of the member 8. Opposed piston rods 18 are connected to the piston and slidably project through the end head 10 of the cylinder; being connected at their outer forward end to a cross bar 19. Another piston rod 20 conects to bar 19 centrally between rods 18, and extends into a two-way hydraulic ram 21. This ram is supported by rigid arms 22 projecting from the barrel 1, and is spaced from said barrel a sufficient distance to allow of movement of the piston rod and cross bar unit through a stroke of such length that piston 17 may move from a point adjacent end head 10 and ahead of the hopper intake 23 (as shown in dotted lines in Fig. 2) to a point adjacent the rear end of cylinder 4, as shown in full in said figure.

The ram is provided with flexible conduits 24 which extend to operating equipment (not shown) supported from and movable along the ground to one side of the trench, and controlled by an operator stationed at such equipment.

In operation, with the machine disposed in the bottom of the trench 3, the ram is actuated to retract the piston 17 to its position clear of the hopper intake, and the cylinder is then filled with concrete; the mix of which is of relatively stiff nature, attained by predetermined proportioning of the ingredients.

The piston is then advanced, which pushes the concrete 25 into the barrel portion 2, while at the same time the concrete becomes compacted because of the gradually decreasing width of the area between the barrel portion 3 and the core 7, and into which area the concrete is forced.

With repeated concrete feeding and piston advancing strokes, the concrete is extruded from the rear end of the machine in pipe form; the barrel portion 2 being sufliciently thin that the outside diameter of the formed pipe is not materially altered as it leaves the machine.

As the piston 17 is moved away from the concrete on its return stroke, any concrete which may have dripped from the hopper is pushed out from the cylinder through an opening '26 in the end'head at the bottom thereof.

As the pipe becomes laid in the trench, its frictional contact with the ground is such that the pipe has greater resistance to movement along the ground than the smooth sur'faced'barrel and shoe. As a result, once an initial piece of pipe is projected into the trench, further laying of the pipe in the trench is caused by a backing away of the machine from the pipe already'laid. This of course is "because of the pressure exerted by the hydraulic fluid inthe ram '21 against the forward end head 21a of the ram, and since the ram is rigidly tied to the barrel, the piston unit in efiect stays in a stationary position relative to the ground, while the barrel itself moves forwardly. In other words, the machine intermittently advances of itself along the trench, leaving the pipe be hind, and thus requiring no motive power, other than suflicient hydraulic pressure in the ram, to propel it.

In order to stiffen the pipe and prevent possible collapse of the same before the concrete has thoroughly set, the barrel portion 2 is formed along :its sides with slots 27 which extend upwardly from the horizontal central plane of the .barrel, and are open to the rear end thereof, as shown in Fig. 1. A flange 28 extends along and projects outwardly from the upper edge of each slot; the outer edge of the slot lying in the vertical plane of the center of width of the barrel, or so as to engage the side of the trench at the corresponding level. At the forward end of the slot and flange a vertical lateral web 29, depending from the flange, fills in the space between the barrel above the center thereof and the adjacent portion of'the wall of the trench.

As a result of this arrangement some of the concrete being forced through the barrel is extruded through the slots 27', forming substantially triangular ribs 30 integral with the pipe and filling in an area of the trench which would otherwise 'be unoccupied by a purely cylindrical pipe. The uppermost and unsupported portion of the pipe is therefore prevented from tending to spread laterally, with an accompanying sag or partial collapse of the'pipeat the top, and instead the pipe retains its desired cylindrical form on the outside.

When it is desired to clean out the machine, as is of course necessary aftera'pipe laying operation is comp'let-ed, thecleaning may be greatly facilitated by removing-the core '7. 'To do this, it is only necessary to rotate the sleeve in a-direction to-unscrew the member 9 from the head 10; the outer exposed end portion of the core beingprovided with opposed holes31 for the reception of a'lever pipe or rod to serve as a turning tool. Also, by reason of the removabilityof member 7, another similar member, but with a different diameter of rear-end portion 11, may be mounted in the machine sov that pipes of different thickness may be formed without any major change in the machine beingnecessary.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fulfill the objects of the invention as set forth herein.

While this specification sets forth-in detail the present and preferred construction of the device, still in practice suchdeviations therefrom may be resorted to as do not form a departure from the spirit of the invention, as defined -by the appended-claims.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

1. A pipe forming and laying machine comprising an elongated barrel adapted to be disposed lengthwise in and to rest on the bottom of atrench in which the pipe is to be laid, thebarrelbeingopen .at one end, a core in the barrel symmetrical to the peripheral contour thereof at said one end and spaced fromsaid. endto leave a space about the peripheryofthe barrel inwardly thereof whose width determines the thickness of the pipe to be laid, means to feed concrete into :the barrel :adjacent its other end, means mounted in connection with the barrel to advance concrete along the barrel from the point of feed to cause such concrete to be extruded from said one end of the barrel and, into the trench in ,pipe form, and means provided with the barrel to form lateral shoulders on the pipe as it is extruded into the trench; said shoulders engaging the sides ,of the trench and extending upwardly apredetermined distance from the upper end of the lower curved portion of the trench.

2 A machine as in claim .1, in which said shoulder forming meanscomprises longitudinal slots formed in the barrel ,onoppositesides and open to-saidone end of the barrel, the lfower edge ofeach slot being substantially in the central transverse. planeof the barrel, and a flange projecting outwardly from the upper edge of each slot and adapted to extend -.to .the side wall of the trench at the corresponding level.

3. Ina pipe forming and laying machine, an elongated barrel adapted to be disposed lengthwise in a trench in whichxthe pipetis to be laid and including a forward portion to rest on thebottomof the trench and a rear portion-to receive-the concrete to beextruded from-the machine, thebarrelbeing open at 'its forward end, an end head on the; rear .endof the barrel, a longitudinal rigid core in the'barrel, :thecoreincluding a relatively light weight for-ward rBOIIlOIl within the forward portion of thejgbarrelandspaeed therefrom, the spacing of saidcore portion from 5th; barrel at the openend thereof determining the-thicknessof the pipe to be formed, and a relatively-small :but heavy duty member rigid with and projecting .rearwardly :from.-:-said :forward .core .portion centrally-:thereof and'rremovabiy projecting into and rigidly supported by the end head. 

